Viscoelastic polyurea copolymers are a class of polymeric materials that have found a wide variety of uses, including uses such as coatings (including release coatings), adhesives (including pressure sensitive adhesives), gaskets, tubing, vibration dampening materials and the like.
Many of these viscoelastic polyurea copolymers are polydiorganosiloxane-based copolymers. The unique properties of these copolymers are derived mainly from the physical and chemical characteristics of the siloxane bond and the organic substituents. Typically the outstanding properties of polydiorganosiloxane copolymers include resistance to ultraviolet light, extremely low glass transition temperature, good thermal and oxidative stability, high permeability to many gases, very low surface energy, low index of refraction, good hydrophobicity and good dielectric properties.
Traditionally viscoelastic polyurea copolymers have been prepared in solution. The dissolved copolymer is then cast or coated and dried.